4. How many mL of a 0.150 M sodium iodide solution must be added to 75.0 mL of a 0.250 M lead (11) nitrate solution to precipitate all of the lead?
5. The neutralization of 25.0 mL of 0.24 M hydrochloric acid requires 5.0 mL of barium hydroxide.
What is the molarity of the barium hydroxide solution?

Agas is inside a cylinder fitted with a piston. the gas and its surroundings are both at 20 ∘c and the gas is compressed as the piston moves and decreases the cylinder volume. the compression takes place slowly enough to allow the gas temperature to stay at 20 ∘c and the work done on the gas by the compression is 2.4 × 103 j.